1.\" -*- nroff -*- 2.\" 3.\" Copyright (c) 1996 Doug Rabson 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $FreeBSD$ 30.\" 31.Dd June 5, 2007 32.Os 33.Dt VOP_OPEN 9 34.Sh NAME 35.Nm VOP_OPEN , 36.Nm VOP_CLOSE 37.Nd open or close a file 38.Sh SYNOPSIS 39.In sys/param.h 40.In sys/vnode.h 41.Ft int 42.Fn VOP_OPEN "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td" "struct file *fp" 43.Ft int 44.Fn VOP_CLOSE "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td" 45.Sh DESCRIPTION 46The 47.Fn VOP_OPEN 48entry point is called before a file is accessed by a process and the 49.Fn VOP_CLOSE 50entry point is called after a file is finished with by the process. 51.Pp 52The arguments are: 53.Bl -tag -width mode 54.It Fa vp 55The vnode of the file. 56.It Fa mode 57The access mode required by the calling process. 58.It Fa td 59The thread which is accessing the file. 60.It Fa fp 61The file being opened. 62.El 63.Pp 64Pointer to the file 65.Fa fp 66is useful for file systems which require such information, e.g., 67.Xr fdescfs 5 . 68Use 69.Ql NULL 70as 71.Fa fp 72argument to 73.Fn VOP_OPEN 74for in-kernel opens. 75.Pp 76The access mode is a set of flags, including 77.Dv FREAD , 78.Dv FWRITE , 79.Dv O_NONBLOCK , 80.Dv O_APPEND . 81.Sh LOCKS 82.Fn VOP_OPEN 83expects 84.Fa vp 85to be locked on entry and will leave it locked on return. 86.Pp 87.Fn VOP_CLOSE 88expects at least a reference to be associated with the vnode and does not 89care whether the vnode is locked or not. 90The lock and reference state is left unchanged on return. 91Note that 92.Fa vn_close 93expects an unlocked, referenced vnode and will dereference the vnode prior 94to returning. 95.Sh RETURN VALUES 96Zero is returned on success, otherwise an error code is returned. 97.Sh PSEUDOCODE 98.Bd -literal 99int 100vop_open(struct vnode *vp, int mode, struct ucred *cred, struct thread *td, 101 struct file *fp) 102{ 103 /* 104 * Most file systems don't do much here. 105 */ 106 return 0; 107} 108.Ed 109.Sh SEE ALSO 110.Xr vnode 9 , 111.Xr VOP_LOOKUP 9 112.Sh AUTHORS 113This manual page was written by 114.An Doug Rabson . 115